US biopharmaceutical company Biohaven Ltd. (NYSE: BHVN) said on Wednesday it has agreed a global licensing and collaboration deal giving South Korea-based SK Biopharmaceuticals exclusive worldwide rights to its Kv7 ion channel platform led by opakalim.

Opakalim is a selective Kv7.2/7.3 potassium channel activator in Phase 2/3 development for focal epilepsy, and is being evaluated in two randomised, placebo-controlled studies, with topline results from the RISE3 trial expected in the second half of 2026. The drug is a once-daily oral therapy that has been studied in more than 1,200 participants.

SK Biopharmaceuticals will advance opakalim through development and regulatory approval and provide commercial infrastructure for the medicine worldwide.

Biohaven will receive USD400m in near-term cash, comprising USD350m at closing and USD50m in 2027, and is eligible for USD150m in development and regulatory milestones. SK Biopharmaceuticals will also make up to USD795m in upfront and milestone payments related to the Kv7 platform and pay tiered US royalties ranging from the mid-teens to low twenties, plus mid-single digit royalties outside the US.

SK Biopharmaceuticals will assume future Kv7 programme costs, including up to USD185m in milestone obligations to Knopp Biosciences upon US and EU approval and a mid-single digit worldwide royalty, as well as up to USD60m in additional milestone commitments for future Kv7 pipeline programmes.

Closing is subject to regulatory review.